<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    /*id选择器*/
    #p1{color: #665151}
    /*类选择器*/
    .c1{color: #4e530f}
    /*分组选择器*/
    h4,#p1,.c1{background-color: #ddf3f1}
    /*属性选择器*/
    input[type="text"]{color: lightslategray}
    /*任意元素选择器*/
    /*边框: 粗细 样式 颜色*/
    *{border: 1px solid #777466}
  </style>

</head>
<body>

<input type="text">
<input type="password">

<p id="p1">苹果</p>
<p class="c1">香蕉</p>
<p>橘子</p>
<h3>冰箱</h3>
<h3 class="c1">洗衣机</h3>
<h3>电视机</h3>
<h4>张三</h4>

</body>
</html>